1. Field of the Invention
This invention relates to wear gauges, and more particularly, to a wear gauge for measuring tape head wear in a magnetic tape recording system and to a method of measuring tape head contact pressure distribution and wear.
2. Description of the Related Art
In magnetic recording systems, the mechanical interaction of the magnetic head and the recording medium is an important factor determining the performance and reliability of the system. Ideally, the head is in contact or near contact with the moving recording medium to optimize read/write processes. The contact at the head/medium interface results in wear which is a major concern affecting performance and lifetime of both head and medium.
In magnetic tape and disk recording systems, considerable effort has been made to determine the wear resistance of magnetic head materials in contact with the recording media. As recording density increases, knowledge of the head wear characteristics becomes of increased importance, since even very small dimensional changes at the surface of the head can contribute to performance degradation of the recording system.
A common procedure for determining head wear is to run the head for an extended period in operative contact with the moving magnetic medium. For example, U.S. Pat. No. 4,091,654 discloses a method for testing abrasion of a recording head. According to this patent, the smoothness of a simulated head made of polished steel or other material is measured before and after a given amount of contact with a recording surface using a fiber optic emitter/detector to measure light reflected from the surface of the head. However, this type of test does not measure the wear rate or identify specific wear regions on the head.
U.S. Pat. No. 3,753,093 discloses a device for determining the wear rate of a simulated recording head in contact with a moving magnetic tape. The surface of the simulated head contacting the tape has deposited thereon strips of magnetic alloy similar to the alloy of an actual recording head. During the tape transport operation, the increase of the electrical resistance of magnetic alloy strip is monitored to measure the rate of wear of the magnetic alloy strip. This type of test requires a complex procedure for depositing the magnetic alloy strips and electrical contacts and does not provide a good measure of the microscopic wear profile.
There is an ongoing need for a wear gauge and method of use providing a simple and inexpensive tool for evaluating head wear and head/media compliance in magnetic recording systems. The present invention provides an improved wear gauge and method of use addressing this need.